Numerical study of hydraulic jumps on corrugated beds using turbulence models


Abstract: Hydraulic jumps have been used for dissipation of kinetic energy downstream of hydraulic structures, such as spillways, chutes, and gates. It was found that if jumps were made to occur on corrugated beds, tail water and length of jumps reduced significantly. During the formation of the hydraulic jump on a corrugated bed, the flow is turbulent water and air mixing together. In the present study, 2-dimensional numerical simulation of hydraulic jump on a corrugated bed was evaluated using both standard k-\varepsilon and RNG k-\varepsilon models. The free surface was determined using the VOF method. The results showed that k-\varepsilon turbulent model and VOF method for predicting the water surface in the jump on a corrugated bed were suitable and the relative error of predicted water surface profiles and measured value were within a range of 1\%-8.6\%. The study of the axial velocity profiles at different sections in the jump found that velocity profiles in different experiments were similar and there was a good agreement between modeled and measured results. The effects of corrugations (t, s) on the basic characteristics of jump, such as free surface location, velocity, and shear stress distribution, were studied for a different range of Froude number.

Keywords: Hydraulic jump, corrugated bed, Navier-Stokes equations, volume of fluid (VOF), k-\varepsilon turbulence models.

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